What’s this wear mark?

[Rflshootr]

I special ordered the stock directly from McMillan and those marks definitely weren't there when I got it or I would've sent it back. Not sure how it would affect one pillar and not the other except that the front pillar has better, more uniform contact with the receiver. I always torque the action screws to Savage's specifications with a torque screwdriver.

It could have been from when they laid up the stock. It may have a void that you can't see or it may just be that your action mates poorly and put too much stress in that area. That's what a proper bedding job takes care of. No matter if the action or the inlet of the stock is mis machined, bent, twisted, warped or bowed, or whatever, proper bedding makes for a perfect fit with 100% contact between the 2.

 

[Rflshootr]

Do you have a picture of the trigger guard mortise and the bottom of the rear pillar? Do you use a metal or plastic trigger guard?